Many long term wheelchair users develop back pain and/or spinal and pelvic deformities due to the rounded spinal posture promoted by the sling upholstery in the standard wheelchair. In Phase I of the Back Support Shaping System project, seven different back supports were designed, fabricated and evaluated by 69 subjects during a brief clinical assessment. The adjustable, dynamic back supports reshape sling back upholstery, provide postural support and allow folding of the wheelchair without removal. The objectives of Phase II are: l) to refine the design problems identified in Phase I, 2) to assess the durability and ease of use, and 3) to evaluate the posture, comfort, and function of 40 subjects using the back supports over a period of one year. Strength testing will be performed to ensure sufficient product durability. The one year clinical assessment will evaluate changes in posture, comfort, external pressures at the seating surface, upper extremity skills, pulmonary function, wheelchair propulsion, and wheelchair-user stability. The results of this project will guide the development of prototypes for beta testing at seating clinics around the country. The back supports will potentially improve posture, comfort and function in persons using wheelchairs with sling back upholstery.